The Italian gun-making company Luigi Franchi Spa produced its first submachine gun, designated as LF-56, in 1956. This was a prototype weapon that bore more than a passing similarity to the prototype submachine guns designed couple of years earlier by Beretta in the process of developing the PM 12 submachine guns. Next year, Franchi began production of a slightly improved weapon, designated LF-57. This weapon was adopted by Italian Navy in 1962, but competition from other designs, most notably the Beretta's Model 12 and Heckler und Koch's MP5, limited sales of this basically good weapon, which, nevertheless, remained on the market until late 1980s, mostly because of export sales to certain African countries. In around 1962 Franchi also introduced a semi-automatic version of the LF-57, known as Police Model; this weapon had longer barrel (406mm) and was exported and sold commercially in USA.

Franchi LF-57 submachine gun is blowback operated, full-automatic only weapon which fires from open bolt. The bolt is shaped like an inverted "L", with most of its mass being located above the barrel and in front of the breech face. The receiver, along with pistol grip and magazine housing, is made from two stamped steel halves, left and right. Barrel is held at the front of receiver by a screw-on nut. There are no manual safeties on the gun, but an automatic safety is provided in the form of a large button, located below the trigger guard on the front of the pistol grip. The shoulder stock is made from thin steel tubing and folds forward and to the right. Sights are fixed.